Effects of Friction Stir Process Parameters on Microstructure and Mechanical properties of Aluminum Powder Metallurgy Parts

Document Type: Research Paper

Authors

1 Young Researchers and Elite Club, Najafabad Branch, Islamic Azad University, Najafabad, Iran

2 Department of Materials Engineering, Isfahan University of Technology, Isfahan, Iran

Abstract

The effects of friction stir processing (FSP) on the microstructure and mechanical properties of aluminum powder metallurgy (PM) parts was investigated. PM parts were then subjected to FSP at advancing speeds (v) of 40-200 mm/min and tool rotational speeds (ω) of 800-1600 rpm. Microhardness (HV) and tensile tests at room temperature were used to evaluate the mechanical properties of the friction stir processed specimens. In order to evaluate microstructure of processed zone, cross-sections of FS processed specimens were observed optically. Based on the results obtained from investigation of the Zener-Holloman parameter (Z), average grain size decreased with decreasing working temperature and increasing working strain rate (equal to increasing Z). The finest grain size was ~ 5.4µm obtained at ω=1000 and v =100 mm/min corresponding to a strain rate of 27s-1 at 414 . This sample exhibited, the best mechanical properties with microhardness, yield stress, and tensile strength of the 43 Hv, 82 MPa, and 118.3 MPa, respectively.

Keywords

Main Subjects


[1]    R. S. Mishra, M. W. Mahoney, S. X. McFadden, N. A. Mara, and A. K. Mukherjee, “High strain rate superplasticity in a friction stir processed 7075 Al alloy,” Scripta Mater. J., vol. 42, 2000, pp. 163–168.

[2]    W. B. Lee, Y. M. Yeon, and S. B. Jung, “The improvement of mechanical properties of friction-stir-welded A356 Al alloy,” Mater. Sci. Eng. A J., vol. 355, 2003, pp. 154–159.

[3]    Z. Y. Ma, R. S. Mishra, and M. W. Mahoney, “Superplasticity in cast A356 induced via friction stir processing,” Scripta Mater. J., vol. 50, 2004, pp. 931–935.

[4]    R. S. Mishra, Z. Y. Ma, and I. Charit, “Friction stir processing: A novel technique for fabrication of surface composite,” Mater. Sci. Eng. A J., vol. 341, 2003, pp. 307–310.

[5]    C. J. Hsu, P. W. Kao, and N. J. Ho, “Ultrafine-grained Al-Al2Cu composite produced in situ by friction stir processing,” Scripta Mater. J., vol. 53, 2005, pp. 341–345.

[6]    A. S. Golezani, M. Esmaily, and N. Mortazavi, “A study on the sub-structure and mechanical properties of friction stir processed AA 6061-T6 joints with ultra-fine grained structure,” Adv. Mater. Process. J., vol. 2, 2014, pp. 33–46.

[7]    M. Abbasi Gharacheh, A. H. Kokabi, G. H. Daneshi, B. Shalchi, and R. Sarrafi, “The influence of the ratio of ‘rotational speed/traverse speed’ (ω/v) on mechanical properties of AZ31 friction stir welds,” Mach. Tool. Manu. J., vol. 46, 2006, pp. 1983–1987.

[8]    Ø. Frigaard, Ø. Grong, and O. T. Midling, “A process model for friction stir welding of age hardening aluminum alloys,” Metall. Mater. Trans. A J., vol. 32, 2001, pp. 1189–1200.

[9]    T. R. McNelley, S. Swaminathan, and J. Q. Su, “Recrystallization mechanisms during friction stir welding/processing of aluminum alloys,” Scripta Mater. J., vol. 58, 2008, pp. 349–354.

[10]     K. N. Krishnan, “On the formation of onion rings in friction stir welds,” Mater. Sci. Eng. A J., vol. 327, 2002, pp. 246–251.

[11]     X. Cao and M. Jahazi, “Effect of welding speed on the quality of friction stir welded butt joints of a magnesium alloy,” Mater. Design J., vol. 30, 2009, pp. 2033–2042.

[12]     K. Elangovan and V. Balasubramanian, “Influences of pin profile and rotational speed of the tool on the formation of friction stir processing zone in AA2219 aluminium alloy,” Mater. Sci. Eng. A J., vol. 459, 2007, pp. 7–18.

[13]     C. I. Chang, C. J. Lee, and J. C. Huang, “Relationship between grain size and Zener–Holloman parameter during friction stir processing in AZ31 Mg alloys,” Scripta Materi. J., vol. 51, 2004, pp. 509–514.

[14]     W. J. Arbegast and P. J. Hartley, “Friction Stir Weld Technology Development at Lockheed Martin Michoud Space System - An Overview,” in TRENDS IN WELDING RESEARCH -INTERNATIONAL CONFERENCE, 1998, pp. 541–546.

[15]     K. Elangovan and V. Balasubramanian, “Influences of tool pin profile and welding speed on the formation of friction stir processing zone in AA2219 aluminium alloy,” Mater. Proc. Tech. J., vol. 200, 2008, pp. 163–175.

[16]     F. J. Humphreys and M. Hatherly, Recrystallization and related annealing phenomena, 2ed. University of Manchester Institute of Science and Technology, Oxford, 2004, p.417.  

[17]     C. Rhodes, “Fine-grain evolution in friction-stir processed 7050 aluminum,” Scripta Mater. J., vol. 48, 2003, pp. 1451–1455.

[18]     M. Pareek, A. Polar, F. Rumiche, and J. E. Indacochea, “Metallurgical evaluation of AZ31B-H24 magnesium alloy friction stir welds,” Mater. Eng. Performance J., vol. 16, 2007, pp. 655–662.

[19]     Y. S. Sato, M. Urata, H. Kokawa, and K. Ikeda, “Hall-Petch relationship in friction stir welds of equal channel angular-pressed aluminium alloys,” Mater. Sci. Eng. A J., vol. 354, 2003, pp. 298–305.

[20]     T. Hirata, T. Oguri, H. Hagino, T. Tanaka, S. W. Chung, Y. Takigawa, and K. Higashi, “Influence of friction stir welding parameters on grain size and formability in 5083 aluminum alloy,” Mater. Sci. Eng. A J., vol. 456, 2007, pp. 344–349, 2007.